Re: [PATCH 7/7] ftrace, perf: Add filter support for function traceevent

From: Frederic Weisbecker
Date: Wed Dec 21 2011 - 17:08:05 EST


On Wed, Dec 21, 2011 at 07:56:31PM +0100, Jiri Olsa wrote:
> Adding support to filter function trace event via perf
> interface. It is now possible to use filter interface
> in the perf tool like:
>
> perf record -e ftrace:function --filter="(ip == mm_*)" ls
>
> The filter syntax is restricted to the the 'ip' field only,
> and following operators are accepted '==' '!=' '||', ending
> up with the filter strings like:
>
> "ip == f1 f2 ..." || "ip != f3 f4 ..." ...

Having the functions seperated like this sort of violates the
grammar of the filtering interface.

The typical way to do this would have been to stringify the
functions: ip == "f1 f2"

I feel a bit uncomfortable with "ip == f1 f2" scheme but perhaps
we can live with that. Especially as otherwise that would
require us to type "ip == \"f1 f2\"" for the whole filtering expression.

Thoughts?
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